Most airless electric sprayers locate the relatively heavy electric motor above the paint receptacle or even above the sprayer handle and thus the user's hand. At these locations the heaviness of the magnet and stator gives a wobbly feel to the sprayer when held in spraying position. Moreover, in such sprayers, the handle is located back of the paint receptacle and the motor which requires the user to counterbalance the combined masses with his wrist. This is uncomfortable and tiring to a user attempting to apply paint in a workmanlike manner. For comfortable balance, it has been discovered that an improved airless electric sprayer could be obtained by arranging for the paint receptacle and the motor to counterbalance each other so that the user need only apply a supportive vertical force for the entire unit. It has also been learned that placement of the paint receptacle and the magnet and stator comprising the motor below the hand significantly improves balance for ease of operation. This problem has been efficiently solved in the disclosed improved sprayer.
In further attaining ease of use of an electric sprayer, the invention further provides for the quick release and reattachment of the paint receptacle with its specially formed closure to the sprayer housing. The receptacle need not be unscrewed from the housing but by a simple action of the user the receptacle with its closure may be quickly removed from the housing. This prevents spillage and also allows for interchangeability from a paint receptacle to a receptacle containing paint thinner or similar solvent to clean the sprayer and then to a different paint.
During the course of spraying, quite frequently the user wants to put the entire unit down to survey his accomplishments or temporarily halt operation for some other reason. In providing solutions to many of the problems encountered in spraying, the invention further provides a built-in non-tipping stand or placement feature by which the sprayer unit is supported upon a flat surface by not only the bottom rim of the receptacle but also by a foot extending downwardly from the motor housing integrally therewith. With this positive standing ability, the likelihood of tipping is minimized.
Airless electric sprayers may become clogged due to paint seepage back along the piston inside the cylinder. A few sprayers provide a drain communicating with the piston cylinder located at a position such that when the piston takes an intake stroke it moves past the drain port, opening the cylinder to the drain for return to the receptacle of unspent paint. Such residual paint can nonetheless still move backward along the piston possibly entering parts of the mechanism and causing clogging or sticking problems.
Frequent and thorough cleaning of the entire pump and liquid delivery mechanism ensures operability of the sprayer for each new job. An access panel is provided in the housing to expose the pump assembly and the structure is otherwise designed for convenient cleaning.
A further benefit to the user provided by the improved sprayer comprises a specially formed piston having a reduced diameter central portion which advantageously allows the drain port to open along the length of the piston where unused paint may accumulate for direct return to the receptacle without necessitating piston travel beyond the drain.
The invention further allows the user to not only comfortably hold the sprayer but also to grasp it in close proximity behind the nozzle, almost as if it were an extension of the index finger, for accurate control over the direction of the spray emission.